Lieutenant-Commander Trellian is the Chief Medical Officer of the U.S.S. Bellerophon, an Intrepid class star-ship, NCC-74705.
CHIEF MEDICAL OFFICER: Medical department only. The chief medical officer, also known as ship’s surgeon, or ship’s doctor, is responsible for the health and wellbeing of the crew and other persons aboard the ship, and leads the ship’s medical department. A chief medical officer can order, and countermand the orders of, senior officers where matters of that officer’s health are concerned. When aboard the ship, the chief medical officer always has the Advantage “Medical Department”, which represents the ship’s medical personnel.